1. Field of the Invention
The invention relates to innovative polyestersiloxane acrylates, to their use as additives in radiation-curable coatings and printing inks, and to processes for preparing them.
The innovative polyestersiloxane acrylates display outstanding properties as additives in radiation-curing coatings, printing inks and/or print varnishes. The innovative polyestersiloxane acrylates are highly compatible with liquid coatings, printing inks and/or print vanishes, possess polymerizable groups, thereby minimizing the risk of migration of constituents of additives, and promote the leveling and the wetting properties of the still-liquid coatings, printing inks and/or print varnishes. The cured coatings, printing inks and/or print varnishes exhibit improved resistance to soiling by felt tip pens (“marker resistance”), without the slip properties of the cured coating being made unsatisfactory.
2. Description of the Related Art
Radiation curing by UV light or electron beams is a rapid, efficient, and environmentally benign way to cure polymerizable monomers or oligomers. Absence of emissions, low investment costs, and low energy requirement as a result of short drying units, high production rates by virtue of rapid curing, and, in many cases, enhanced quality of the coating, especially with regard to gloss and abrasion resistance, are reasons why, in the field of industrial coatings, radiation curing constitutes the application form which is showing the greatest expansion.
Radiation-curing coatings, printing inks and/or print varnishes are known and are described in, for example, “UV & EB Curing Formulations for Printing Inks, Coatings & Paints” (R Holman, P. Oldring, London 1988).
There is a growing demand for additives for coatings and print varnishes which raise the resistance of the coating to soiling of all kinds. Soiling as a result of felttip pens is particularly unwanted (“marker resistance”, “antigraffiti effect”). The harm caused by marker pen contamination on furniture, floors, walls, and other surfaces is immense.
In order to increase the marker resistance, as it is known, of radiation-curable coatings and print varnishes it is nowadays customary to use fluorine compounds and/or silicone polymers (EP-A-0 493 172, WO-A-98/03574).
A drawback of these fluorine and/or silicone compounds, however, is that they have to be used in relatively large amounts in order to obtain a sufficient protective effect (comonomers, copolymers).
Because they often do not react with the binder during the process of curing, the additives may migrate from the cured coating and/or print varnish and be manifested as a disruptive film on the surface.
The fluorine and/or silicone compounds are often very incompatible with the coating and/or print varnish, with the possible consequence of clouding and surface defects (craters, orange peel, dimples) in the coating.
Furthermore, such additives significantly lower the friction coefficient of the coating, producing slippery surfaces. In the field of floor coating in particular (woodblock flooring, linoleum, PVC) such an effect is undesirable, since the floor coating must be secure underfoot. The friction coefficient of the coating must therefore exceed a certain minimum.
Accordingly there is a growing demand for additives for radiation-curable coatings and/or print varnishes which contain radiation-curable groups, are highly compatible, improve the marker resistance of coatings and/or print varnishes, and do not render the slip properties of the coating unsatisfactory.